Self-adjusting recirculating overflow



Dec. 18, 1951 .1. a. CRAWFORD SELF-ADJUSTING RECIRCULATING OVERF'LOWFiled March 24', 195.0

INVENTOR.

HTTO/P/VEX Patented Dec. 18, 1951 SELF-ADJU STING RECIRCULATING OVERFLOWJames B. Crawford, Los Angeles, Calif., asslgnor to Paddock PoolMaintenance 00., Los Angeles, Calif., a corporation of CaliforniaApplication March 24, 1950, Serial No. 151,777

16 Claims. 1

This invention relates to apparatus for swimming pools, tanks and likereceptacles, and more particularly to equipment for removing surfaceliquid in and on which scum, dust, leaves and other debris tends togather to the detriment both of the appearance of the pool and ofenjoyment of the users.

A principal object of the'invention is to provide novel surface skimmingequipment which has improved means for regulation of the swimming rate.

Another object is to devise equipment of the described type consistingof a minimum number of parts which are of simple design and inexpensiveto manufacture.

Another object is to provide apparatus which is easy to install andself-adjusting in operation.

Still another object is to provide for easy adjustment and control ofthe quantity and rate of removal of surface liquid.

Still other objects and advantages will be apparent from the detaileddescription which follows.

A present preferred embodiment of the present invention consistsessentially of two parts, a float member and a fixed support which isconnected to an outlet. The two parts have a telescoping relation witheach other and together form an open chamber in which a quantity of theliquid in the pool or tank is segregated and separated from the mainbody of the liquid. This chamber will vary in size with changes in thedepth of liquid in the pool which cause upward or downward movement ofthe float member. By withdrawing liquid continuously from the chamber adifierential in liquid levels of pool and chamber is created whichaifects the buoyancy of the float member with the result that thismember is caused to float below the liquid level of the pool but abovethe liquid level in the chamber. As a result a top layer of liquidspills over the top of the float member and into the chamber whence itis withdrawn by gravity or by a pump through the outlet connection tothe fixed support. The fioat member automatically adjusts itself to thedifference in liquid levels created by the withdrawal of liquid from thechamber.

In order to illustrate the invention and the manner of its use concreteembodiments thereof are shown in the accompanying drawings in which: 7

Figure 1 is a diagrammatic view partly in vertical section and partly inelevation of a portion of a swimming pool with a skimming deviceinstalled;

Figure 2 is a vertical sectional view on an enlarged scale through oneform of skimming device during operation, the section being taken on theline 2-2 of Figure 3 with the outlet pipe shown in elevation;

Figure 3 is a plan, view on a reduced scale of the device shown inFigure 2; and

Figure 4 is a vertical sectional view similar to Figure 2 through amodification of the invention.

In Figure 1 is illustrated a typical installation of equipment of thepresent invention in a swimming pool, the surface water which iswithdrawn being filtered and then returned to the pool. The skimmingdevice indicated generally at A, and of either of the types illustratedin detail in the other figures of the drawing, is mounted on outlet pipeB at the edge of pool C. Outlet pipe has a hand-operated control valve Din advance of a pump E of any suitable or desired type, the dischargeline F of the pump leading to a filter G of known or suitable type andthence by line 1-! back into the pool. When the withdrawn liquid is notrecirculated, the pump E and filter G may be omitted and withdrawalefiected solely by gravity fiow.

Referring now to Figures 2 and 3 for a detailed showing of one form ofthe skimming device A, the latter comprises a chamber formed of but twoparts 6 and 1 in telescoping relation with each other. Part 6 is a fixedmember in the form of a plate or disk attached horizontally to theupturned open end of outlet pipe B at a' suitable distance below thelevel of the body of liquid in pool C. Mounted for vertical movement andenclosing fixed member 6 is float member I open at both ends butprovided at its upper end with an internal sealed annular air chamber 8formed by inner wall 9, bottom wall l0 and top wall ll. Bottom wall IIIwill engage the upper face of plate 6 to act as a stop whenever the bodyof liquid in pool C is at or below the top 01. outlet pipe B. In theform shown plate 6 is circular and float member I is cylindrical but itis to be understood that these parts can be made in other shapes such assquare, oval, triangular, etc. if desired. There is sufiicient clearancebetween the outer edge of plate 6 and the skirt or lower portion offloat member 1 which telescopes therecver to permit free upward anddownward movement of float member 1 as the liquid level a in the poolchanges. When liquid is not being withdrawn by outlet pipe B, floatmember I rides or floats in the pool with its annular fiat top H wellabove the surface a, the two parts 6 and I cooperating to provide achamber above plate 6 3 and enclosed by the portion of float member 1above plate 8, this open chamber containing a body of liquid which issegregated from the main body in/pool C.

The device functions as follows: On opening valve D in outlet line Bliquid will be withdrawn from the open chamber above plate 8 either bygravity or by the operation of pump E. The level of the liquid in thechamber will fall. This will automatically effect a change in theposition of float member 1 relative to plate 8 since there is lessliquid in the open chamber and hence a lower liquid level there. MemberI will preforce move floats below the level a of the main body andsurface liquid will pour over the top H and into the open chamber,member 1 finding a point of balance or equilibrium with the level offluid in the open chamber at a position such as b (Figure 1) as comparedwith level a of the main body. It is usual practice to set the flowthrough outlet pipe B so that float member I adjusts itself with its topabout A; of an inch below main liquid level a.

A low narrow upstanding annular flange or lip l2 may be provided at theouter edge of top H of float member 1. This has been found to have thefurther effect of enlarging (so to speak) the mouth or central openingin member 1 which admits the overflow liquid into the chamber aboveoutlet pipe B, thereby increasing the draw of the device; in other wordsoverflow begins at flange l2 instead of at the inner edge of top H as isthe case when flange I2 is omitted. Flange or lip l2 may also beutilized to retain a flat screen (not shown) on the top of float memberI to intercept and retain leaves and other debris which might clog pipeB or foul pump E.

Part 6 and I may be made of any suitable or desired material. Metals notsubject to corrosion, such as copper and brass are suitable. Thepreferred materials, however, are plastic compounds such as certain ofthe well-known phenol-condensation products including Lucite, tenite,etc. Since there are no critical tolerances, part I as well as part 6may be inexpensively molded of plastic such as Lucite which in additionto its inherent suitability also presents an attractive appearance.formed in two parts of equal size by a split mold operation and thenintegrally united to form the sealed float chamber 8.

Dimensions of the parts of the overflow or skimming device shown inFigures 2 and 3 for a typical installation are as follows: Plate or disc6 is of Lucite plastic inch and 71%" in diameter. It is formed withflutes or depressions 6a on its upper face, as shown, to reduce weight.A central opening is drilled and tapped to screw on to the upturnedvertical end of outlet pipe B. Float member I, also of Lucite plastic,has walls in thickness throughout. The internal diameter of the lowerend or skirt which telescopes over plate 6 is 7%", providing clearancewith plate 6. The reduced opening or mouth defined by air chamber 8 atthe upper end has a diameter of 4%". The upstanding annular flange i2 is3 2" in height. This size is adequate for most pools; for very largepools the dimen- Float member I may be initially 4 sions are increasedor two devices of the specified size may be utilized advantageously.

Figure 4 shows a modification in which a substantially fluid tight sealis maintained between the plate and float members at certain depths ofliquid in the pool but at lesser depths free access of fluid to outletpipe B is permitted. In this form A, the fixed plate or disc member I isupwardly flared from a hub portion Ma which is threaded onto theupwardly directed end section of outlet pipe B, which section has aseries of small openings in its side wall beneath a cap 26 which closesthe top of the pipe, openings 25 being located above hub portion lid ofplate or disc member I 8 but below a horizontal projection of the upperend of the latter. The outer edge of member I6 is recessed or otherwisearranged to receive and hold' a packing ring lib which bears against thetelescoping lower skirt .portion of float member H to form asubstantially fluid tight seal but the packing ring has a hard smoothouter surface which offers a minimum of frictional resistance tomovement of float member ll. Toward its upper portion the skirt of fllat member "is outwardly expanded in a smm th curve 21 into an enlargedoffset which disposes its wall 28 out of contact with plate l8 andprovides clearance around packing Ila. Above section 28 float member I!has an inwarlly extending annular sealed air chamber l8 formed by innercylindrical wall is, bottom wall 20 and top wall 2|, In this form flattop 2| extends radially beyond chamber 18 and the cylindrical wall ofmember II. Top 2| may have a low, narrow upstanding flange or lip 22around its edge.

The device of Figure 4 is made in a similar manner and operatessimilarly to the first form of the invention previously described exceptthat when the main body of liquid falls to a predetermined level thedescending movement of float member l1 brings the expanded outwardlycurved wall 21 of the offset to and below packing lib on fixed plateiii, the liquid removed by pipe B is no longer conflned to that whichspills over top 2! but will include liquid moving upwardly through thelower end portion of member 11 and around packing I61) and into the wideclearance space between the latter and wall 28 provided by the enlargedoffset. Liquid will continue to pass in this manner through this lowerpassageway to outlet pipe B in unrestricted volume until level a of themain body has fallen to such an extent that bottom wall 20 of floatchamber l8 comes to rest on the peripheral upper edge of fixed plate I6.As the pool is refilled to restore it to its original level, floatmember II will rise and sloping wall 21 will guide its lower skirtportion into telescoping relation again with plate l6. Cap 26 on theupper section of outlet pipe B and small outlet opening 25 will screenout leaves and large pieces of debris but a fine, mesh screen (notshown) seated on top 2| or surrounding the upper end ofskimming device Ais still desirable in most instances.

- From the above it will be apparent that the equipment of the presentinvention for skimming and like operations is extremely simple both inor 11- is not more than one-eighth inch below the the system dependsupon the rateat .which'the skimmed liquid is drawn offv by thecirculation I Y pump, or by the drain" pipe in the case of a grav-' itytype outflow. Thisis in contrast to previously known skimming devicessupportedbya float which floats entirely in the pool liquid, and the[position of whose overflow lip ishighly sensitive .to the buoyancy oithe float. Adjustment of such devices to skim at the desired rateis veryI level of. the body of liqu'idiwhich is being skimmed. It will be seen'that the sensitivity of difiicult, while by contrast, the skimming rateof the presentdevice depends upontheliquidlever b maintained inside thedevice, and hencedk rectly upon the easily controll'ed rateoifoutflowthroughpipe B.

1 The invention has been illustrated inl its appli cation to swimmingpolls but is directly useful generally wherever surfacelayers are to'berelm ovedfrom bodies of liquid/for any purpose and especially when thisis to be done'with a mini-' mum of disturbance of lower layers ofliquid.By, utiliz ing a packing or seal between the flxedplate flii ai-id thefloatingmember l1, seepage between these parts such as occurs betweenmembers 6 and i lbfli'igures 2 and 3, is'avoidedj as for the skim,mingdevice of Figures ;4' an d 5, so long as the. I bodyof liquid ismaintainedpata sufficiently hi h lev'eljjto ke'ep enlarged .joffs'et'ior flared] wall 211' above' plate; l6 (as in' 'F i'gure 4) only liquid'from' the surface can be withdrawn-through pip B I 7 5 While theinvention ihas b'een hereinmsclosed ln-what iare now believed tobe'pr'e'ierred ferment, it;- is to be understood "that; the inventionis/not; l mited "to o the specific details thereof but co ersallichangfefi: modific tio s and adap'tationswith in thescope of jthappendedclaims. 1 {I e1aim: I a; L' '1; v

j; r ,1.- In equipment for skimining swimming{poo' tanks and .the like.containing e bOdYQEOI liquid) ,thecombination or: sideandfbottom wall ari ii hamberizp s J nearthesurface thereo andconstruclted and fd f iigel1 1 11; vf-frorn teniain'jbod of mme se V ni e q ant t -of i u di egeeated tionsfoi {the located said body of liquid s d am enwa l ide wallmember id t work n I telescoped a open chamber,

chamber, .said member having a liquid overflow lip'fpositionedjnear thesurface or the main body oirliquidand overwhich surface liquid from saidmain body; may ,spill into said chamber, float meansfoperativelyconnected to said movable wall and ar'ranged to;float in the liquidcontained inside saidf chamber, whereby said over-flow lip will rise'and ifall with the liquid level inside said chambenjan outflowconduitfor removing liquid ,from'said chamben and a circulation pump connecte'dween outflow conduit.

'j 3-. skimming device for pools, tanks and the fllke comprisingaflxedly supported circular plate, a ,cylindrical-.membergtelescopedover said plate with aslidable fit :gin'g an air chamb' v agl a stopf'toengage the latter to limit the downwardjmovement of said member, the topwall of v said chamber forming an annular'flat top for said member] overwhich liquid will flow intothe open chamberabove said plate formed bysaid cylind i lx I 'chamberjis'lowered' by withdrawing fluid from saidopen chamber, and an outflow conduit for jme 'son said member providv'esaid plate and serving ember when; the liquid level in said openremoving liquid from said chamber.

41A skimmingqdevice for pools, tanks and the like-comprising a fixedlysupported circular plate,

flat a'nn'ular top, a low flange extending above 'said top around theedge thereof,;a'nd an outflow I conduit for removing liquid from saidchamber.

5. 'fA skimming device for. pools,,tanks and the a e compr is in g a,fixedly supported horizontally et.

disposed plateafloat member open atboth ends having a 'skirts'jportion'in telescoping relation with'said plate I and a sealed air chamber abovesaideplate,"said) float member and said plate co- -,9perating tdprovide.aniop en chamber for seggregalting ai guanltfity of liquid in the pool from the frnain body of liquid, said air, chamber being withinsaid open chamber so as to float in the iqiiid contained th'erewithin,said float member hav' g ,afiat top which projects beyond hereof overwhich liquid from the flow-intoflsaid openchamber when depressedby'withdrawal of liqmsa ,openphaniber, and an outflow conernvingfliqui'ci from; said chamber. mining device for pools, tanks and therising a 'flxe'dly supportedhorizontally circular plate, la cylindricalfloatineint foth gends havingjits lower portion said plate for'verticalmovement he toand having'a sealed air champlate, said float member andsaid chamber open at the top to hold ty of the liquid in the poolseparate from ome nee therewithin, fsaid float g. a flat annularjtop'which extends ,tic'alwalls thereof, over which top aid cl'iamber. v

skimmingdevicefifor pools, tanks and the e inainbody of liquid, saidairchamber being 4 within said open chamber so as to float.

and arrbutflow fcond uit fonremoving liquid from J.

in isin a fixedly. supported circular plate,

a cylindrical float member having a skirt telescoped over said platewith a close sliding lit to form with said plate a chamber open at thetop for segregating a quantity of liquid from the main body of liquid inthe pool, float means within the oonflnes of said member above saidplate, said member having an annular flat topover which liquid from themain body flows into said chamber where said member moves downwardlybeneath the level of the main body of liquid in response to withdrawalof liquid from said open chamber, said member having an enlargingofl'est intermediate its ends to permit liquid to by-pass said plate andenter said chamber from beneath when the main body 01 liquid falls to apredetermined level, and an outflow conduit for removing liquid fromsaid chamber.

8. A skimming device for pools, tanks and the like comprising incombination a circular plate having a packing'ring on its outer edge,and a cylindrical member open at both ends having a skirt portion totelescope over said plate and to slidably engage said packing ring tomake a fluid tight seal, a float inside and connected to saidcylindrical member, said member having an enlarged oifset portion topermit liquid to by-pass said plate in certain positions of said memberrelative to said plate, and an outflow conduit for removing liquid fromsaid chamber.

9. A skimming device for pools, tanks and the like comprising incombination a circular plate having a packing ring on its outer edge,and a cylindricalmember open at both ends having a skirt portion totelescope over said plate and to slidably engage said packing ring tomake a fluid tight seal, a float inside and connected to saidcylindrical member, said member having an enlarged oiIset portion topermit liquid to by-pass said plate in certain positions of said memberrelative to said plate, said ofiset portion of said member joining saidskirt portion thereof in a smooth curve to permit free movement of saidmember into and out of fluid tight sealing engagement with said plate,and an outflow conduit for removing liquid from said chamber.

10. In skimming equipment for swimming pools, tanks and the like thecombination with a vertical outlet pipe of an upwardly dished platemounted on said pipe, said plate having a packing ring on its outeredge, an open-ended float member having a skirt portion telescoped oversaid plate to engage said packing ring and form a fluid tight seal,float means on the upper portion 01. said member to engage said plate asa stop to limit the downward movement of said member on said plate,means on said member providing a by-pass for fluid around said plate assaid member approaches the lower limit of its movement.

11. In skimming equipment for swimming pools, tanks and the like thecombination with a vertical outlet pipe of an upwardly dished platemounted on said pipe, said plate having a packing ring on its outeredge, an open-ended float member having a skirt portion telescoped oversaid plate to engage said packing ring and form a fluid tight seal,float means on the upper portion of said member to engage said plate asa stop to limit the downward movement of said member on said plate,means on said member providing a bypass for fluid around said plate assaid'member approaches the lower limit of its movement, said pipe havinga closed end and ports in its side wall above said plate but below ahorizontal Drojection of its upper end.

12. In equipment for skimming swimming pools, tanks and the like thecombination of a circular palte mounted horizontally beneath the surfaceof a body of liquid, and a cylindrical float member supported by theliquid in telescoping relation with said plate, said member having anair chamber partially closing the upper end thereof, said float memberand said plate forming a chamber in which a quantity of liquid isseparated from the main body of liquid, and means for withdrawing liquidfrom said chamber automatically to depress said float member relative tosaid plate and to cause liquid from the main body to overflow saidmember into said chamber.

13. In equipment for skimming swimming pools, tanks and the likecontaining a body of liquid, the combination of: a chamber positioned insaid body of liquid near the surface thereof and constructed andarranged to hold a quantity of liquid segregated from the main body ofliquid, said chamber being partly deflned by fixedly mounted wall meansand partly deflned by a vertically movable side wall structure having anoverflow portion over which liquid from the main body can spill intosaid chamber when said overflow portion is lowered below the level ofsaid main body, and float means operatively connected to said movableside wall structure and arranged to float in the liquid inside saidchamber, whereby said overflow portion of said side wall structure willrise and fall with the liquid level inside said chamber, and an outletfor removing liquid from said chamber.

14. A skimming device for pools, tanks and the like comprising a.fixedly supported horizontally disposed plate, a float member open atboth ends having a skirt portion in telescoping relation with said plateand a sealed air chamber above said plate, said float member and saidplate cooperating to provide an open chamber for segregating a quantityof liquid in the pool from the main body of liquid, said air chamberbeing located within said open chamber so as to float in the liquidcontained therewithin, said float member having an overflow edge overwhich liquid from the main body will flow into said open chamber whensaid member is depressed by withdrawal of liquid from said open chamber,and an outflow conduit for removing liquid from said chamber.

15. In equipment for .skimming swimming pools, tanks and the likecontaining a body of liquid, the combination of: an open chambercomprising a fixedly supported bottom wall structure, a side wallstructure surrounding said bottom wall structure and movable verticallyrelative to said bottom wall structure in sliding engagement with theperiphery thereof, said chamber having an overflow portion over whichliquid from the main body can spill into said chamber when said overflowportion is lowered below the level of said main body by withdrawal ofliquid from said chamber, a float included in the chamber located insidethe chamber and operatively connected to said side wall structure, so asto float in the liquid contained inside the chamber, whereby saidoverflow portion of the chamber rises and falls with the liquid levelinside the chamber, and an outlet for removing liquid from said chamber.

I 16. In equipment for skimming swimming pools, tanks and the likecontaining a body of liquid, the combination of: an open chambercomprising a fixedly supported bottom wall structure, a side wallstructure surrounding said bottom wall structure and movable verticallyrelative to said bottom wall structure in sliding engagement with theperiphery thereof, an over flow lip on said side wall structure overwhich liquid from the main body can spill into the chamber when saidoverflow lip is lowered below the level oi said main body by withdrawalof liquid from said chamber, a float fixedly connected to the side wallstructure and arranged inside ber, whereby the said overflow lip risesand falls with the liquid level inside the chamber, and an outlet forremoving liquid from said chamber. JAMES B. CRAWFORD.

REFERENCES CITED file of this patent:

Number UNITED STATES PATENTS Name Date Carlisle Aug. 12, 1902 Post ..1Jan. 31, 1905

